Tialf to lambert v



Patented Apr. !8, !899. A. W. WATERS.

BACK PEDALING BRAKE.

(Application filed Nov. 5, 1897.)

(No Model.)

%Madh Urta ,TATES 'ATENT rripa,

ALFRED lVILLlAM VVATERS, OF TORONTO, CANADA, ASSIGNOR OF ONE- 'HALF TO LAMBERT Vf DUSSEAU, OF SAME PLACE.

BACK-'PEDALING BRAKE;

SPECIFICATION forming part of Letters Pat-exit v. ezaeer, dat-,ed April s, 1899.

Application filed November 8, 1897. Serial No. 657347. (No model.)

To all whort ?lt may 'conccrn:

Be it known that I, ALFRED VVILLIAM VVA: TERS, superintendent, of the city ot' Toronto, in the county of York and Province of Ontario, Canada, have invented a certain new and Improved Hub-Brake for Bicycles, -of which the following is a specification.

The object of my invention is to devise a brake for bicycles which will be simple, quicklyset to give any desired degree of frietion, and which when set Will stay set till released by the rider; and it consists, essentially, of a friction-drum non-revolubly supported upon. the aXle of the rear wheel, a disk fast upon the hub within the drum, one or more friction-dogs adapted to slide upon the said disk, and a sprocket-wheel loose upon .the hub and provided with a spiral thread upon its outer face adapted to engage a similar thread cut upon the friction-dogs, so that 'the revolution of the sprocket-wheel in one direction will force the dogs into contact with i the drum to brake the wheel and in the other direction will draw them into contact with the disk to drive the wheel, the whole being arranged substantially as hereinafter more specifically described and then definitely claimed.

Figure l is a crosssection of my improved brake. Fig. 2 is an inside face View of the frietion dogs, disk, and friction-drum. Fig. 3 is an outside face View of the device, partly broken away to eXpose the spiral threads u pon the sprocket-wheel.

In the drawings like letters of reference indicate corresponding parts in the different figures.

A is the aXle of the rear wheel, rigidly secured in the frame in the usual manner, a portion of which frame is shown in dotted lines in Fig.

B is the hub of the rear wheel, suitably supported by ball-bearings about the axle A.

C is a friction-drum supported upon the axle A and held from turning in any suitable nanner, preferably by havinga pin a inserted in its outer face, which may engage with a portion of the frane of the machine, though in sone cases it might be sufficient to merely screw it upon the axle, as shown.

D is a disk Secured upon the hub B in any suitable manner, preferably by being threaded thereon, as shown in Fig. 1. This disk is grooved at b to receive one or more frictiondogs E, which lie within the rim c of the drum C. Heads dare preferably formed upon each dog E to present as broad a friction-surface as possible to the rim of the friction-disk, and also to enable the dog to engage with the edge of the disk D when drawn inward toward the hub. It is not essential, however, that the heads should engage the disk, as the pressu re of the dogs upon the inner ends of the grooves b will answer the same purpose. Upon the face of each dog I form a segment of a spiral thread e, which is adapted to engage with the spiral thread f, formed upon the face of the sprocket-wheel F. This sprocket-wheel is loose upon the hub B, and is always held in engagement with the friction-dogs by the tlange g upon the hub.

Having described the construction of my device, I will briefiy set out its mode of operation.

When the sprocket-wheel F is revolved in the direction indicated by the arrow in Fig. 3, as in the action of forward pedaling, the spiral thread upon its face eng-aging with the threads upon the dogs causes the latter to retract and the heads of the dog firmly grip and jamb upon the outer edge of the disk D, preventing any further revolution of the sprocketwheel upon the hub. The latter is then in driving connection with the sprocket-wheel till by the action of back pedaling the latter ,is revolved in the opposite direction, when the dogs are released from contact with the disk and forced outwardly into contact with the inner surface of the rim c of the frictiondrum O. Friction is immediately set up between the friction-dogs and the drum, so that an effectual brake is put upon the action of the wheel. As the pitch of the spiral thread is preferably comparatively small, the sprocketwheel will remain in the exact position to which it has been turned till it is either revolved farther backward to increase the frietion or turned forward to again drive the bicycle.

It will be readily understood that the effectiveness of the brake is wonderfully added to by the fact that when the brake has once ICO been set it remains set till the sprocket-wheel is again moved.

The ease with which the brake can be set to give a greater or less degree of friction according to the position to which the sprocketwheel is turned is a most important advantage derived from this peculiar Construction, and enables a rider to retard the motion of his wheel sufficiently to enable him to coast down the steepest hill or to bring his wheel to a sudden stop, as may be desired.

In constructing my brake the details of construction may be materially varied without depart ing from the spirit of the invention. Other means might be adopted, forinstance', for holding the friction-drum from rotating, forconneeting the disk D to the hub, and for slidably supporting the friction-dogs therein.

From the above description it will be seen that I have devised a very simple and effieient brake for bicycles, which fulfils the important function of being quickly set by backpedaling to give any desired degree of frietion, and which when set.- will stay set till released by the rider, thus eontinuing the braking action even though the chain should break.

As the threads forned on the dogs only engage with the spiral threads on the face of the sprocket-whecl for a short distance during pedaling and back pedaling, it is obvious that a segment of one or more spiral threads with appropriate pitch for each dog will suffice without having a continuous spiral, as indicated in the drawings, or a single thread may be forned on the friction-dog and the face of the sprocket-wheel so shaped as'to engage therewith.

I am aware that it is old to provide a backpedaling brake wherein a series of balls, rollers, or wedging devices is moved by a series of inclined faces, so that said balls, rollers, or wedging devices come in contact with a friction-drum, and therefore make no claim to any such Construction, as I regard my invention as essentially different therefrom. I deen it important that the rotatable member have one or more radial grooves therein and that the friction-dogs be provided with stems which are supported in and have a longitudinal radial movement in said radial grooves, for the reason that such a construction permits of giving the friction-dogs such a. firm support and hearing as would be impossible with the device above referred to.

\Vhat I claim as my invention isl. In a bicyele, an axle and a stationary drum carried by the said axle, in combination with a hub afriction-dog movahly supported upon the said hub within the drum and provided upon its face with a segment of a spiral thread; and a sprocket-wheel loose upon the hub and suitably threaded to engage the said dog and expand it within the drum when the rider back-pedals, substantially as and for the purpose specified.

2. Ina bicyele, an axle and a stationary drum carried by the said axle, in combinatiou with a hub; a disk rigidly connected to the hub within the drum; one or more frictiondogs slidable in radial grooves formed in the said disk and each provided upon its face with a segment of a spiral thread and a sprockctwheel loose upon thehub and suitably threaded to engage the said dogs and to force them into contact with the drum or the disk according to the direction in which it is' rcvolved, substantially as and for the purpose specified. r

3. In a bicyele, the combination of the axle A; the hub B; the friction-drum C, stationary upon the said axlc; the disk D, fixed to the said hub and grooved at b; one or more friction-dogs E, set in the grooves b and provided with heads (Z, and segmental spiral threads e; and the sprocket-wheel F, loose on the hub B, and provided with the spiral thread f to engage the threads e, substantially as and for the purpose specified.

4. In a bicyele, the combination of the axle A; the hub B, havinga fiange g formed thereon; the friction-drum C, stationary upon the said axle; the disk D, fixed to the said hub and grooved at b; one or more friction-dogs E, set in the grooves b and provided with heads d, and segmental spiral threads c; and the sprocket-wheel F, loose on the hub l, and provided with the spiral thread f, to engage the threads e, substantially as and for the purpose specified.

5. A bicyele hub-brake comprising the following instrumentalities: a frictioi-drum secured to the axle, a rotatable disk secured to the hub, one or more friction-dogs with one or more threads formed thereon and slidably connected to the disk, a sprocket-wheel loose on the hub with the face so shaped as to engage with the thread or threads on the frietion-dogs, substantially as described and for the purpose specified.

Toronto, October 25, 1897.

ALFRED XVILLTAM \VA'I`ICRS. 

